1. The Field of the Invention
This invention is directed to apparatus for reclaiming heat of combustion associated with calcining kettle means.
2. Description of the Prior Art
It is known that a mixture of gas and air can be passed through a porous wall so that combustion takes place over a large area of the wall on the side opposite to the side first impinged by the gas and air. Reference is directed to Holden U.S. Pat. No. 2,828,813 of Apr. 1, 1958, and the safety construction for a luminous wall furnace patent of Holden U.S. Pat. No. 3,008,513 of Nov. 14, 1961.
The examples of prior art show a concern for too much heat build-up in the furnace wall so that there is a danger of a back-fire or explosion. Another problem is found that operation of a furnace at a high temperature level can lead to progressive cracking and deterioration of the mortar between bricks, as well as flash back into the plenum chamber that can result in an explosion.